Industrial Internet of Things (IIoT) opens up a challenging research area towards improving secure data sharing which currently has several limitations. Primarily, the lack of inbuilt guarantees of honest behavior of participating, such as end-users or cloud behaving maliciously may result in disputes. Given such challenges, we propose a fair, accountable, and secure data sharing scheme, $\textit{FairShare}$ for IIoT. In this scheme, data collected from IoT devices are processed and stored in cloud servers with intermediate fog nodes facilitating computation. Authorized clients can access this data against some fee to make strategic decisions for improving the operational services of the IIoT system. By enabling blockchain, $\textit{FairShare}$ prevents fraudulent activities and thereby achieves fairness such that each party gets their rightful outcome in terms of data or penalty/rewards while simultaneously ensuring accountability of the services provided by the parties. Additionally, smart contracts are designed to act as a mediator during any dispute by enforcing payment settlement. Further, security and privacy of data are ensured by suitably applying cryptographic techniques like proxy re-encryption. We prove $\textit{FairShare}$ to be secure as long as at least one of the parties is honest. We validate $\textit{FairShare}$ with a theoretical overhead analysis. We also build a prototype in Ethereum to estimate performance and justify comparable results with a state-of-the-art scheme both via simulation and a realistic testbed setup. We observe an additional communication overhead of 256 bytes and a cost of deployment of 1.01 USD in Ethereum which are constant irrespective of file size.

翻译：工业物联网（IIoT）为改进当前存在诸多局限的安全数据共享开辟了具有挑战性的研究领域。首要问题在于缺乏对参与方（如终端用户或云端）诚实行为的固有保障，恶意行为可能导致争议。针对这些挑战，我们提出了一种面向IIoT的公平、可问责且安全的数据共享方案——**FairShare**。在该方案中，由物联网设备采集的数据经中间雾节点辅助计算后，在云端服务器中进行处理与存储。授权客户端可支付一定费用访问这些数据，以制定提升IIoT系统运营服务的战略决策。通过引入区块链技术，**FairShare**能够防范欺诈行为，从而实现公平性——即各方均能获得应得的数据或奖惩结果，同时确保各方所提供服务的可问责性。此外，我们设计了智能合约作为争议调解机制，强制执行结算支付。进一步地，通过适当运用代理重加密等密码学技术保障数据的安全性与隐私性。我们证明只要参与方中至少有一方诚实，**FairShare**即能保持安全性。通过理论开销分析验证了方案的有效性，并在以太坊上构建原型以评估性能，通过仿真实验与真实测试床证明了其与现有先进方案具有可比性。我们观察到，无论文件大小如何，额外通信开销恒定为256字节，以太坊部署成本为1.01美元。